Osteoarthritis
- Fysiobasen
- Sep 10
- 8 min read
Osteoarthritis (OA), also known as degenerative joint disease (DJD), is the most common form of arthritis and is characterized by the gradual breakdown of articular cartilage and subsequent changes in the entire joint structure¹. The disease is divided into primary and secondary osteoarthritis. The clinical presentation varies significantly – from asymptomatic findings on imaging to pronounced joint destruction with severe functional impairment².
Pathophysiology
In healthy joints, the articular surfaces are covered by hyaline cartilage, which provides a smooth surface for movement and functions as a shock absorber. In osteoarthritis, the cartilage gradually degenerates, leading to pain, swelling, and reduced mobility. As the disease progresses, osteophytes (bony outgrowths) may form, and cartilage and bone fragments can loosen, causing mechanical irritation in the joint. The body responds with an inflammatory process in which cytokines and proteolytic enzymes further exacerbate cartilage destruction³. The final stage is characterized by complete erosion of the cartilage surface, where bone rubs directly against bone, resulting in significant pain and structural damage⁴.
Today, osteoarthritis is understood as a comprehensive joint disease – not limited to cartilage alone, but also involving subchondral bone, joint capsule, synovial membrane, ligaments, and surrounding musculature⁴.
Epidemiology
Osteoarthritis is a highly prevalent condition, and its incidence increases with age. In 2017, it was estimated that more than 300 million people worldwide were living with the disease¹. In the United States, 80% of individuals over 65 years have radiographic signs of OA, although only 60% of these present with symptoms. In Australia, 21% of individuals over 45 years reported having OA, with the highest prevalence in those over 80 years⁵. Within the EU, prevalence ranges from 2.8% in Romania to 18.3% in Hungary⁶.
It is important to note that structural changes seen on radiographs do not necessarily correlate with the degree of pain or functional impairment⁷.
Causes and risk factors
The risk factors for developing osteoarthritis are well documented and include:
Increasing age
Female sex
Overweight and obesity
Previous joint injuries (trauma, fractures)
Joint malalignment or axis deviations
Occupational strain and repetitive movements
Weak musculature, especially around weight-bearing joints
Genetic factors and connective tissue disorders such as Marfan syndrome and Ehlers-Danlos⁸,⁹
Primary osteoarthritis develops without identifiable preceding damage and often has a genetic component, particularly among middle-aged women. Secondary osteoarthritis is caused by a known triggering factor, such as joint trauma, infections, or inflammation.
Clinical presentation and symptoms
Osteoarthritis most commonly affects the knees, hips, spine, thumb carpometacarpal joint, first metatarsophalangeal joint, and finger joints. The symptom profile is primarily local and includes:
Pain: Mechanical pain that worsens with activity and improves with rest. Morning stiffness is common but usually subsides within 30 minutes. Pain intensity varies and may worsen with cold or load-bearing activities¹⁰.
Stiffness and reduced mobility: Range of motion restriction develops gradually and is often associated with muscular dysfunction and changes in joint anatomy.
Crepitus and joint sounds: Grating or clicking noises may result from irregular joint surfaces and degenerated cartilage.
Swelling and tenderness: Joint swelling may be mild and caused by synovial thickening or effusion.
Functional limitations: Patients experience difficulties with walking, climbing stairs, and daily activities requiring joint mobility and strength.
It is important to distinguish between disability and total joint locking, which may be caused by loose bodies and requires further evaluation.
Treatment and interventions
The treatment goals for osteoarthritis are to reduce pain, preserve or improve function, and delay further degeneration. This is achieved through a combination of non-pharmacological and pharmacological interventions.
Non-pharmacological interventions (first-line)
Physiotherapy and exercise: A combination of aerobic and strength training has documented effects on function and pain levels. Training must be individually tailored and supervised by a physiotherapist.
Joint unloading: Use of a cane, orthoses, or realignment braces (particularly in knee varus/valgus).
Weight reduction: Reduces mechanical load on weight-bearing joints and can significantly alleviate symptoms.
Ergonomic adjustments and activity modification: Avoidance of strain-inducing activities and guidance on joint-friendly working positions.
Pharmacological treatment (supplementary)
Paracetamol and NSAIDs for pain relief
Intra-articular corticosteroid injections during acute exacerbations
Topical NSAIDs and heat/cold therapy as supportive treatment
In cases of severe joint destruction and failure of conservative treatment, surgical evaluation may be indicated, including arthroscopy or joint replacement⁷.
Treatment of osteoarthritis: pharmacological and physiotherapeutic interventions
The treatment of osteoarthritis (OA) requires a comprehensive approach combining pharmacological agents, physiotherapy, lifestyle modifications, and in some cases surgery. The aim is to reduce pain, improve function and quality of life, and slow disease progression. Osteoarthritis often affects strength, joint mobility, and activity levels, and patients are at increased risk of falls and functional decline⁽¹⁴⁾.
Pharmacological treatment
Pharmacotherapy in osteoarthritis includes oral, topical, and intra-articular medications. Drug therapy should be tailored to the patient’s symptoms, comorbidities, and preferences, and should be combined with non-pharmacological measures.
Paracetamol and NSAIDs
Paracetamol (acetaminophen) and non-steroidal anti-inflammatory drugs (NSAIDs) are first-line options for mild to moderate pain. Oral NSAIDs can be effective but carry a risk of gastrointestinal side effects, especially with long-term use. Topical NSAIDs have fewer systemic side effects but may cause local skin irritation and have somewhat weaker efficacy⁽¹¹⁾.
Intra-articular injections
Used during acute exacerbations or when other treatment is insufficient:
Corticosteroids: Effective in acute inflammation but should be used cautiously due to the risk of cartilage degeneration with repeated injections.
Platelet-Rich Plasma (PRP) and hyaluronic acid: Have been proposed as treatments but still lack solid evidence for osteoarthritis⁽¹¹⁾.
Stem cell therapy and disease-modifying drugs: Are under development, but currently lack approved evidence-based documentation for clinical use in osteoarthritis⁽¹²⁾.
Use of assistive devices
Physiotherapists play a central role in recommending, fitting, and instructing in the use of assistive devices such as:
Cane or crutches (ensuring correct height adjustment)
Orthoses and knee braces in malalignment
Foot orthoses and specialized shoes for gait difficulties
Small aids such as reachers, long-handled shoehorns, and utensils with thick handles
These devices contribute to unloading, functional improvement, and increased independence.
Surgical treatment
In cases of severe joint destruction and insufficient effect of conservative treatment, the patient may be referred to orthopedic surgery. The most common procedures are:
Total or partial joint replacement (especially hip and knee)
Joint correction (osteotomy) in axis deviation
Physiotherapy and exercise
Physiotherapeutic follow-up is essential to preserve function, reduce pain, and promote coping. Treatment goals include:
Improved joint mobility and ROM
Increased muscle strength and endurance
Reduced pain and inflammation
Improved balance and reduced fall risk
Enhanced aerobic capacity and weight control⁽¹⁴⁾
Example of a treatment plan⁽¹⁵⁾ (for patients without acute inflammation or severe cardiovascular disease):
Warm-up and joint mobilization
Strength training: quad sets, straight leg raises (SLR), hip extension in prone, isometric knee extension in sitting, single-leg leg press, standing hamstring curls, and heel raises
Aerobic training: cycling, treadmill, or hydrotherapy
Cool-down and stretching: quadriceps, hamstrings, calf muscles
Gait training and functional exercises
All exercises should be performed bilaterally and adapted to the patient’s functional level and pain tolerance.
Manual therapy
Systematic reviews show that manual therapy combined with exercise can reduce pain and improve function in knee osteoarthritis⁽¹⁶⁾. Examples include:
Mobilization with movement (MWM)
Joint mobilization (patella and tibiofemoral)
Soft tissue treatment and muscle energy techniques
Agility training and balance/perturbation
Agility training and balance exercises are beneficial for older adults with instability or a history of falls.
Agility techniques⁽¹⁷⁾: side stepping, “braiding,” crossover steps forward and backward, shuttle walk, reaction drills with directional changes.Perturbation techniques: balance boards, unstable surfaces, external disturbances (push/pull), combined balance and strength training.
Fall prevention
Patients with osteoarthritis have an increased risk of falls (30% higher incidence) and fractures (20% increased risk), due to reduced balance, muscle strength, and side effects of medications (e.g., dizziness with opioid use). Physiotherapists should include fall-prevention strategies such as strength, balance, and gait training in the treatment plan⁽¹⁴⁾.
Differential diagnostic considerations
If pain patterns and findings are atypical, consider the following differential diagnoses⁽¹⁹⁾:
Periarticular conditions: bursitis, tendinitis, or enthesopathy
Inflammatory arthritis: morning stiffness >60 minutes, warmth, erythema, and involvement of MCP joints, wrists, elbows, and shoulders suggest RA or another systemic disease
Systemic diseases: unexplained weight loss, fever, fatigue, or night sweats may indicate rheumatic disease, malignancy, or infection
Crystal arthropathies: suspicion of gout should be investigated with joint aspiration and synovial fluid analysis
Diagnostic procedures and outcome measures in osteoarthritis
In the diagnosis and evaluation of osteoarthritis, both imaging and clinical measurement tools are used. These provide important insights into the severity of the disease, its progression, and how it affects the patient’s function, pain experience, and quality of life.
Radiological assessment: Kellgren and Lawrence classification
The most widely used method for radiological grading of osteoarthritis is the Kellgren and Lawrence scale⁽²⁰⁾. This scale is particularly applied in the assessment of knee osteoarthritis and divides the disease into four grades based on radiographic findings:
Grade I: Normal joint structure with minimal osteophyte formation. No significant joint space narrowing.
Grade II: Presence of osteophytes in two locations, mild subchondral sclerosis, but normal joint space and no bone end deformities.
Grade III: Moderate osteophyte formation, early deformities of bone ends, and initial narrowing of the joint space.
Grade IV: Large osteophytes, pronounced bone end deformities, marked joint space narrowing, pronounced subchondral sclerosis, and the presence of cysts.
This classification provides important information about structural changes but has limited correlation with the patient’s symptom experience. Radiographic findings alone are therefore not sufficient to assess function or pain.
Standardized outcome measures for osteoarthritis
To evaluate treatment effects, the disease’s impact on daily life, and pain, various validated questionnaires and scales are used.
Outcome measures focusing on pain
WOMAC
HOOS
KOOS
Oxford Hip Score / Oxford Knee Score
McGill Pain Questionnaire – Short Form
Outcome measures focusing on daily function and quality of life
SF-36
WHOQOL-BREF
PASE
LEFS
KOOS (used for both pain and ADL)
Use of these measures enables physiotherapists to:
Quantify the patient’s pain and function
Evaluate treatment response over time
Compare interventions
Tailor interventions individually
By combining radiological assessments and patient-reported outcome measures, a more comprehensive picture of the severity of the disease and its impact on the patient’s life can be obtained. This forms the basis for an accurate and targeted treatment plan.
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Trukket
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